Utility knife



May 2.2, 3.956 H. G. BQQTH 2,746J47 UTILITY KNIFE Filed Sept. 8, 1955 Q5 fA-i mi.' um Q3 IM Mmmm 1,72/

United States Patent UTILITY KNIFE Herbert G. Booth, Harrison, N. Y., assigner to David Traum Company, Incorporated, a corporation of New York lt is among the objects of the invention to provide a utility knife that is light in weight, compact and easy to manipulate and which may be carried without likelihood of injury to the person `or clothing of the user, yet may readily be set for use, which unit has but few inexpensive parts that may readily be assembled and disassembled for replacement of the cutting blade in but a few seconds without the use of any tools.

According to the invention, these objects are accomplished by the arrangement and combination of elements hereinafter Idescribed and particularly recited in the claims.

In the accompanying drawings in which are shown one of various possible embodiments of the several features of the invention,

Fig. l is a perspective view of the utility knife,

Fig. 2 is a longitudinal sectional view on a larger scale taken along line 2-2 of Fig. l,

Fig. 3 is a view similar to Fig. 2 taken along line 3-3 of Fig, 2,

Fig. 4 is a transverse sectional view taken along line 4-4 of Fig. 3, and

Fig. 5 is an exploded perspective view of the cutting blade and clamp members.

Referring now to the drawings, the utility knife, which may be formed of any suitable material and preferably is substantially entirely of plastic, desirably comprises a substantially cylindrical elongated casing 11 open at both ends as at 12 and 13, the diameter of the bore 14 of the casing desirably being smaller at the end 12 than at the end 13.

Positioned in the casing 11 is a pair of elongated clamp members 15 and 16, each of which is desirably substantially semi-circular in cross section and has a flat face 17 and 18, respectively. The clamp members 15 and 16, when juxtaposed in face to face relation, form a substantially cylindrical rod which desirably is rounded at one end as at 19. The diameter of the rod desirably increases from the rounded front end 19 to the rear end 21 and at a point between its ends the diameter of the rod is equal to the bore diameter at the end 12 of the casing.

One of the clamp members, illustratively member 15, has a cut-away portion 22 extending from its front end 19 and of depth susbtantially equal to the thickness of an elongated substantially rectangular cutting blade 23 which desirably has an elongated longitudinal slot 24 therethrough. The cut-away portion 22 desirably has an elongated longitudinal boss 25 extending outwardly therefrom and preferably molded integral therewith of length slightly less than the length of slot 24 and the face 18 of clamp member 16 has a recess 26 complementary to boss 25.

The end 13 of the casing 11 is desirably internally threaded as at 28 to receive the correspondingly threaded end 29 of a plug 31 which extends longitudinally from end 13. As shown in Figs. 2 and 3, the inner end 32 of plug 31 may abut against the adjacent ends 21 of the clamp members 15 and 16 to retain the front ends 2,746,147 Patented May 22, 1956 thereof wedged in the reduced bore -diameter end 12 of the casing.

The cutting blade 23 which extends beyond the end 12 of the casing and beyond the rounded ends 19 ofthe juxtaposed clamp members 15 and 16, is desirably protected, when the unit is not in use, by a cylindrical hollow cap 34 which has a conventional clip 20 affixed thereon and which may encompass such cutting blade 23 when retained as by force iit over the end 12 of casing 11.

In assembling the utility knife, one end of blade 23 is positioned on cut-away portion 22 of clamp member 15 with boss 25 extending through the slot 24 in said blade. The clamp member 16 is then positioned against member 15 so that faces 17 and 18 thereof are juxtaposed with the boss 25 extending into recess 26.

The juxtaposed clamp members 15 and 16 with the interposed blade 23 are then positioned in the bore 14 of casing 11 with the blade 23 and rounded ends 19 of said clamp members extending through end 12 of the casing. T he plug 31 is then screwed into end 13 of the casing so that the inner end 32 of the plug will abut against the adjacent ends 21 of the clamp members 15 and 16 to move the latter forwardly.

Due to the fact that the juxtaposed clamp members taper from the rear ends 21 thereof to their front ends 19, when moved forwardly through end 12 of the casing, they will wedge therein securly to clamp the cutting blade 23 therebetween. By reason of such wedging action and the coacting boss 25, slot 24 and recess 26, the cutting blade will be securely retained in position restrained frorn displacement in use.

As the utility knife above described is light in weight and compact, it may readily be carried in a handbag or clipped in the pocket Vof the user. The utility knife has a multiplicity of uses such as a pencil Sharpener, cutting fabric or paper, trimming lace, threads and the like, and in the event the blade should become dull with use, it may readily be replaced in but a few seconds without the need for any tools.

As many changes could be made in the above construction, and many apparently Widely diierent embodiments of this invention could be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. An article of the character described comprising a cylindrical hollow casing open at both ends, the bore diameter of said casing being smaller at one end. than the other, a pair of elongated clamp members in said casing protruding from one end thereof, each semi-circular in cross section forming a substantially cylindrical rod when juxtaposed, the diameter of said rod increasing from one end to the other and being equal between its ends to the diameter of the smaller end of said casing bore, whereby said juxtaposed members will wedge in said casing With the smaller diameter end protruding from the smaller end of the casing and a substantially rectangular cutting blade clamped at one end between said clamp members and extending longitudinally of said casing beyond the protruding end of said clamp members.

2. The combination set forth in claim l in which adjacent faces of said clamp members have an elongated bc-ss and a complementary elongated recess respectively and said cutting blade has an elongated slot through which said boss extends.

3. The combination set forth in claim l in which one of the clamp members has a cut-away portion in its face at one end, of depth substantially equal to the thickness of the cutting blade and one end of said cutting blade is seated on said cut-away portion.

4. The combination set forth in claim l in which one t' the clamp members has a cut-away portion on its ace at ene end of depth substantially equal to the thickness of the cutting blade and one end of said cutting blade is seated on said cut-away portion, said cutting blade having an elongated slot therein and said cutaway portion and the opposed face of the other clamp member having an elongated boss and a complementary recess whereby when said boss extends through the slot in said blade into said recess, displacement of said blade Will be prevented.

References Cited in the tile of this patent UNITED STATES PATENTS Doniger Mar. 29, 

